Silca frame pump question

[Mikeyankee]

Pumping up an Axial Pro after flatting today, my [plastic] Silca head wasn't gripping the presta
stem well enough and I was getting blow-by at around 80
psi. I tightened the black plastic screw without much improvement. Then I tried loosening the screw
past its original position, and was surprised that I could get ~100 psi before any blow-by
occurred. By carefully positioning the head on the valve stem (not inserting the stem too deeply)
I could get closer to 110 psi.

The pump is feather-light and works well enough, but seems to be more finicky in gripping the valve
stem than the Blackburn of Zefal XP frame pumps I have on other bikes.

Is this typical of Silcas? Anybody have any special tricks or techniques to recomment?

Mike Yankee

(Address is munged to thwart spammers. To reply, delete everything after "com".)

 

[Phil Brown]

> Anybody have any special tricks or techniques to recomment?

Campy head. Phil Brown

 

[David L. Johnso]

On Fri, 27 Jun 2003 17:49:50 +0000, MikeYankee wrote:

> Pumping up an Axial Pro after flatting today, my [plastic] Silca head wasn't gripping the presta
> stem well enough and I was getting blow-by at around 80
> psi. I tightened the black plastic screw without much improvement. Then I tried loosening the
> screw past its original position, and was surprised that I could get ~100 psi before any blow-by
> occurred. By carefully positioning the head on the valve stem (not inserting the stem too
> deeply) I could get closer to 110 psi.
>
> The pump is feather-light and works well enough, but seems to be more finicky in gripping the
> valve stem than the Blackburn of Zefal XP frame pumps I have on other bikes.
>
> Is this typical of Silcas? Anybody have any special tricks or techniques to recomment?
>
John, if you ask nice I will give you my old Campy head. Far superior, plus it works much better in
deterring dogs. My pump is trash (but, that is the norm for Silca pumps), but the head is fine.

--

David L. Johnson

__o | Accept risk. Accept responsibility. Put a lawyer out of _`\(,_ | business. (_)/ (_) |

 

[Mikeyankee]

Hey, thanks, Dave! But negatory because:

(1) the Campy head is not retrofittable to the plastic Silca Imperios (which I got at T-town for all
of $5, by the way)

(2) You can probably get $25+ for it on Ebay!!!

Hope to see you in August; will advise.

Meanwhile, the pump issue isn't a problem as much as a curiosity. I played with it in the garage
last night and it seemed to work fine by simply not pushing it too far onto the valve stem.

Regards,

John

Mike Yankee

(Address is munged to thwart spammers. To reply, delete everything after "com".)

 

[Tom Paterson]

>[email protected] (MikeYankee)

>(1) the Campy head is not retrofittable to the plastic Silca Imperios

Hmm, maybe not, I've had several Imperos over the years, all had that same brass thread spigot at
the end... --Tom Paterson

 

[A Muzi]

"MikeYankee" <[email protected]> wrote in message
news:[email protected]...
> Hey, thanks, Dave! But negatory because:
> (1) the Campy head is not retrofittable to the plastic Silca Imperios
(which I
> got at T-town for all of $5, by the way)
>
> (2) You can probably get $25+ for it on Ebay!!!
>
> Hope to see you in August; will advise.
>
> Meanwhile, the pump issue isn't a problem as much as a curiosity. I
played
> with it in the garage last night and it seemed to work fine by simply not pushing it too far onto
> the valve stem.

There were once several patterns of Silca body and various heads. Since about 1973 at least there
has virtually only been the one pattern- square boss with a 9mm thread. That format accepts either a
Silca chromoplastic head or the similar Camagnolo ("superlight" #3346) or the classic Campagnolo
1030/2 chromed steel head . Note that the aluminum sleeve is keyed to the head and turns with the
head. Twist with the pump in one hand and the aluminum sleeve in the other hand.

Regarding the Silca's foibles, the washer inside the head necessarily wears, as in any classic
push-on "express" head. That washer also fits the later-model Silca brass floor pump head and is
very available and cheap. Secondly the Silca pump is quite large in diameter and so pumps a tire in
fewer strokes but with extraordinary effort compared to more modern designs. "Express" heads are
simply pushed onto the valve so the washer wears out faster. When pumping, you'll need to hold the
head/tire/rim in one hand in such a way as to not push against an unsuppported valve. And even
though your Silca Impero looks sleek without its aluminum sleeve, leaving that aluminum sleeve in
place really helps to keep a hot pump from cracking in the final few strokes.

--
Andrew Muzi www.yellowjersey.org Open every day since 1 April, 1971